The Neuroscience Center Behavior Core will establish a centralized resource for the analysis of animal behavior. The objectives of this core resource will be to provide uniform behavioral analysis of rodents employing a variety of behavioral platforms appropriate for the research needs of Salk Institute Neuroscience Center faculty and to provide expertise for the interpretation of results. Behavioral studies are an important component of modern neuroscience research. For example, careful analysis of changes in rat behavior in the radial water maze showed that the ability to learn new tasks decreases with age. These changes were eventually found to be reflected at the cellular level, in particular, in the dentate gyrus of the hippocampus where aging is associated with a reduction in the number of axons in the medial perforant path, as well as the density of synaptic contacts impinging on granule cells. Subsequently this reduction in the input to the hippocampus was found accompanied by a decrease in synaptic plasticity, longterm potentiation has a higher threshold and lasts for a shorter time in aged animals, and there is an agedependent decrease in NMDA receptor-mediated responses - all discoveries stemming from the initial analysis of animal behavior. Several ofthe NINDS-funded investigators at the Salk Institute rely on behavioral testing of rodents as a critical component of their projects and most ofthe others would like to incorporate behavioral testing into their NINDS-funded projects. Although we have considerable amount of appropriate equipment for a broad range of behavioral testing of rodents at The Salk Institute, it is presently distributed at multiple sites across the Institute and is maintained, operated and controlled by investigators in individual labs. This situation either precludes the use of behavioral testing or significantly limits it, as investigators that wish to use it in their projects either have to have funding to purchase the equipment and appropriate space to set it up, and further, become trained with its use, and / or collaborate with investigators that have the equipment and experience for the appropriate tests. Many negative factors though are associated with each of these alternatives and are often sufficient to discourage investigators from integrating behavioral testing into their project. The proposed Behavior Core will consolidate at a single convenient location within the Salk Institute the equipment and expertise necessary to perform a wide range of behavioral testing of rodents (primarily mice, but rats can also be accommodated) relevant to the NINDS-funded research projects. The goal ofthe Behavior Core is to provide uniform and comprehensive service for all NINDS-funded investigators at the Salk Institute. This core will eliminate duplication of resources and provide critical expertise across a broad range of analytical tests needed for the proper performance of behavioral studies. The faculty management and technical staffing ofthe Behavior Core will make behavioral testing accessible to all NINDS funded investigators at the Institute and allow them to properiy integrate it into their projects as warranted, regardless of their background training and expertise. This arrangement will also conserve resources, and in several ways serve as a resource multiplier in addressing the issues under study with NINDS funding. This conservation, as well as the communal influence ofthe properly sized user group of NINDS funded investigators, will make potential resources more readily available to invest in the coming years in additional equipment for behavioral testing to keep abreast of technical and issue-related advances that will benefit the NINDS-funded projects.